The ""Kingdom"" (read Saudi Arabia) unilaterally cuts crude oil prices to $10 per barrel, not only touching off a stock market boom (Green Monday) and revivifying an enervated dollar but also affecting the tenancy of the White House. That's the scenario in this plausibly plotted future-finance entertainment with an upwardly mobile hero--David Harrison, a Manhattan-based consultant funnellng billions of petrodollars into domestic securities markets on behalf of The Kingdom's power elite (they double their money in the wake of the dramatic price announcement). Harrison engineers his financial coup through the resourceful use of a master computer program that controls hundreds of blind trust accounts. And his partner in crime--and love--is Devon Lynde, a money-managing lady with a past (Weatherman membership) who has been recruited by the Islamic underground. Meanwhile The Kingdom's shadowy OPEC Minister and his henchmen orchestrate a scenario in which the born-again president of the U.S., up for reelection, would be replaced in office by a former CIA director whose sympathies are more in accord with Mideastern aspirations. Thomas makes this double-cross game just clever enough; and his amiably amoral account of goings-on in the boardrooms and boudoirs of petropower sneer with conviction--from the offhandedly vulgar metaphors of Houston's independent oil drillers to expletivedeleted converse in the Oval Office. A much-better-than-average contender in the what-if genre; a must for market-watchers with a weakness for fanciful fiction.